The invention is an improvement in a rigid jaw car coupler which is manufactured and sold by the Foundry Group of the Midland-Ross Corporation of Cleveland, Ohio, under the trademark Willison. This coupler is primarily used on mine cars and other similar industrial applications. Rigid jaw couplers of this type utilize a locklifting lever which extends exteriorly of the coupler for operating the locking mechanism to cause disengagement of a pair of interlocked couplers. It is necessary for an operator to go between a pair of coupled mine cars to operate the lever of most couplers in use today.
U.S. Pat. No. 2,951,597 is directed to a locking mechanism for placing the lock of a rigid jaw coupler in a lockset position to permit disengagement of a pair of interlocked couplers. This is accomplished by the use of a specially designed pawl which extends exteriorly of the coupler and holds the locklifting lever and lock in a lockset position until the locked couplers are separated. The disadvantage of this locking mechanism is that, should an operator change his mind about separating the couplers and decide to return the lock and lever to their locked positions, he must step between the coupled cars, grasp the exposed handle of the pawl and lift it to cause disengagement of the locklifting lever from the pawl, so that the lock and locklifting lever can move back to their normal locked positions. Any such operation demanding the presence of the operator between a pair of coupled cars is hazardous to the safety of the operator. The invention is directed to solving this problem by providing a locking mechanism which can return the lock to its normal locked position from a lockset position by an operator standing alongside the cars rather than between them.
Briefly stated, the invention is in a rigid jaw coupler employing a spring biased lock, a locklifting lever for moving the lock between its locked and lockset positions, and a lockset member or pawl for engaging the locklifting lever and holding it and the lock in a lockset position. The locklifting lever is provided with a lug which is designed to slidably engage and become interlocked with a cam that is carried by the pawl to hold the locklifting lever in its position. The contour of the cam is such that the interlocked lug can override the cam when the lever is returned to its normal rest position where the locking mechanism is in a locked position. It is not necessary to manually operate the pawl. It is only necessary to operate the locklifting lever which is usually accomplished through linkage that is coupled to the lever and extends to the side of the car employing the couplers. Thus, it is unnecessary for an operator to go between a pair of coupled cars and this hazard has been eliminated at least in connection with the operation of the couplers.